Hypersonic jet hits over 3,300 mph, started at Wright-Patt

An unmanned experimental aircraft, that traces its genesis to the Air Force Research Laboratory at Wright-Patterson, has made history by reaching five times the speed of sound during the longest air-breathing, scramjet powered hypersonic flight.

On its fourth and final test May 1, the $300 million X-51 Waverider program reached a zenith when the aircraft reached more than 3,300 miles per hour and traveled more than 230 nautical miles in six minutes after being dropped from the wing of a B-52 bomber flying over a Pacific Ocean test range at 50,000 feet.

Nearly a decade ago, Wright-Patterson researchers began work on the Waverider setting the foundation for future hypersonic technology that could revolutionize the battlefield, officials said. The technology could one day push commercial flights faster than ever before and set the stage for reusable spacecraft.

“The technology was born here,” Charlie Brink, X-51 program manger at AFRL’s Aerospace Systems Directorate at Wright-Patterson, said Thursday. “It was nurtured here.”

The Air Force could pursue the technology into a next generation hypersonic strike weapon in the mid to late 2020s capable of hitting targets within minutes, or the development of high-speed military drone and surveillance aircraft, officials said. Today, cruise missiles travel at less than the speed of sound.

“Hypersonic technology allows the Air Force to respond extremely quickly to far away contingencies and potentially to out run any defense when it arrives in a war zone,” said Loren B. Thompson, a defense analyst with the Lexington Institute in Arlington, Va. “The Air Force has been researching hypersonics for well over a decade and clearly believes it could have a major impact on military operations if it becomes affordable.”

The military selected Boeing and Pratt & Whitney RocketDyne to develop the airframe and engines. The Defense Advanced Research Projects Agency and NASA teamed with the Air Force Research Laboratory on the project.

Joseph Vogel, Boeing X-51 project manager, said commercial applications of hypersonics could follow in the future shortly after the military fields the technology in the years ahead.

However, Thompson had doubts the technology would happen soon.

“As of today, there are no obvious commercial markets for hypersonics and that is mainly because the investment costs are so prohibitive, but the day may come when traveling to the other side of the world becomes a one-hour experience rather than a one-day experience,” he said.

“When it fires, it vibrates the airplane and it just feels great because you know its working,” said Maj. Andrew Murphy, a B-52 pilot on the final mission, said in a conference call Thursday.

During last week’s test, a rocket booster kicked the X-51 skyward after release. Within seconds, the craft relied on a scramjet engine powered by a special blend of kerosene jet fuel, which officials said was akin to “lighting a match in a hurricane.” The X-51 plunged into the ocean once the fuel was exhausted.

The JP-7 fuel, which will douse a match dropped into it, was the same that once powered the legendary and record-setting SR-71 Blackbird spy plane, officials said.

Other hypersonic vehicles have been powered by hydrogen and hauled huge amounts of liquid oxygen, which are both heavy, costly and not easily handled logistically, officials said.

In a visit to AFRL’s Research Cell 22, engineers tested components of the scramjet in a rarely found propulsion wind tunnel to learn how the engines worked, Wright-Patterson aerospace engineer Glenn Liston said, among other locations where testing occurred around the nation.

The X-51’s successful flight followed the failure of two previous tests, and marginal success of another. “I think like many times you learn more from your failures than you do from your successes,” Brinks said.